It is well documented that essentially all HIV-1 infected individuals develop antibodies capable of binding HIV-1 envelope, but that only a small subset of these antibodies are neutralizing and capable of blocking viral entry in target cells. See e.g. Doria-Rose N. “HIV Neutralizing Antibodies: Clinical Correlates and Implications for Vaccines” The Journal of Infectious Diseases (2010) Volume 201, Issue 7, Pp. 981-983. Over the time of an infection, some individuals develop neutralizing antibodies, and with some of these neutralizing antibodies having activity against diverse primary HIV-1 isolates. A number of broad neutralizing monoclonal antibodies (mAbs) have been identified from HIV-1 infected individuals and these define specific regions on the virus envelope, e.g. CD4 binding site, V3 loop, membrane proximal region (MPER) of gp41, that are vulnerable to neutralizing Abs.
Broadly neutralizing HIV-1 antibodies have been isolated only from natural HIV-1 infection. See e.g. Mascola and Haynes, Immunological Reviews (2013) Vol. 254: 225-244. Some examples of broadly neutralizing antibodies (bnAbs) targeting CD4 binding site or V3 loop are VRC01, CH103, CH31, CH98, 8ANC131, PGT121, PGT128. Unfortunately, so far none of these antibodies have been developed for HIV prevention or treatment. Thus, the need exists for monoclonal broadly neutralizing antibodies that can be developed and used for prevention and treatment for an infectious agent, such as HIV.